Anti-soil redeposition composition for drycleaning

ABSTRACT

THE PRESENCE OF A SMALL ABOUNT OF CALCIUM CHLORIDE IN A DETERGENT-CONTAINING DRYCLEANING SOLVENT WILL REDUCE THE REDEPOSITION OF SOILS ONTO TEXTILE FABRIC.

United States Patent 3,707,508 ANTI-SOIL REDEPOSITION COMPOSITION FOR DRYCLEANING Rodney A. Blomfield, Painesville, Ohio, assignor to Diamond Shamrock Corporation, Cleveland, Ohio No Drawing. Continuation-impart of abandoned application Ser. No. 4,751, Jan. 21, 1979. This application July 12, 1971, Ser. No. 161,977

Int. Cl. C09d 9/00; Clld 7/22, 7/50 U.S. Cl. 252-162 Claims ABSTRACT OF THE DISCLOSURE The presence of a small amount of calcium chloride in a detergent-containing drycleaning solvent will reduce the redeposition of soils onto textile fabric.

REFERENCE TO A =CO-PENDING APPLICATION This is a continuation-in-part of US. Ser. No. 4,751 filed Ian. 21, 1970, now abandoned.

BACKGROUND OF THE INVENTION The successful cleaning of textile fabrics involves not only the removal of various soils from the fabrics but also requires a means for reducing the tendency of the soils to redeposit upon the fabric surface.

The first function of removal of the soils from the fabrics is performed rather easily and effectively by a number of detergent materials in both aqueous and nonaqueous systems. The detergents themselves, however, fail to do an adequate job of preventing the soils, once removed, from redepositing upon the fabric.

In aqueous cleaning systems this problem has for the most part been overcome through the use of a wide variety of additives which perform specifically to prevent or reduce soil redeposition. For example, Wide-spread use is made of sodium carboxymethyl cellulose, polyvinyl alcohol and polyvinylpyrrolidone. It has been noted, however, that the same compounds have little or no effect when employed for the same purpose in a drycleaning system, that is, in a system based upon the use of a hydrocarbon solvent, particularly perchloroethylene, trichloroethylene or Stoddards solvent.

The use of drycleaning systems has been on the rise for a number of years both industrially and commercially. Originally, the marked tendency of soils to redeposit on textile fabrics being treated by a dry, as opposed to aqueous, cleaning system was of little import for the reason that most articles drycleaned were dark-colored and/or were outerwear garments which were cleaned only infrequently. For this reason little attention has been given to a chemical solution to the problem of redeposition, most attention being directed to somewhat more cumbersome physical means such as filtration, distillation and the like.

In recent years, however, an increasing demand has arisen in the drycleaning industry for a chemical method for preventing the redeposition of soils on textile fabrics, this demand being due to a large extent to the introduction of permanent press garments. Owing to the chemical nature of the wash-and-wear fibers themselves, as well as the compounds used to impart a permanent press Patented Dec. 26, 1972 finish, it has been found that such garments are particularly susceptible to stains of an oily nature. Since removal of oily stains is difficult, if not impossible, with an aqueous system, the obvious answer to the problem is to resort to a drycleaning system. This is particularly true since the permanent press finish itself is known to be more resistant to repeated cleanings with a solvent-based ssytem than an aqueous system. Unfortunately however, owing to the above-described redeposition problem, drycleaning of permanent press and other fabrics has heretofore remained limited to dark-colored materials.

STATEMENT OF THE INVENTION Therefore, it is an object of the present invention to provide a method and composition whereby the advantages of a drycleaning system for the removal of soils from textile fabrics may be realized without the usual attendant disadvantage of the tendency of these soils to redeposit upon the fabric being cleaned.

It is a further object of the present invention to provide an inexpensive, easy-to-use additive to a detergent-containing drycleaning solvent for use in the cleaning of textile fabrics, which additive will minimize the redeposition of soils upon the fabrics being treated.

These and further objects of the present invention will become apparent to those skilled in the art from the description and claims which follow.

It has now been found that the tendency of detergentcontaining drycleaning solvent ssytems to redeposit soils on textile fabrics being cleaned and in contact therewith is substantially reduced by the addition of a small but effective amount of calcium chloride to the solvent system. By the use of such a simple system a wide variety of textile fabrics may be easily and efficiently cleaned thus obtaining all advantages inherent in the use of a drycleaning system, without the attendant disadvantage of redeposition of a considerable quantity of the soil removed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The term drycleaning solvent as used throughout the specification and claims is intended to refer to any of the hydrocarbon-based solvents used for this purpose, the most commercially significant of which are trichloroethylene, perchloroethylene and Stoddards solvent.

It has to date been found that most of the detergent formulations generally in commercial use for drycleaning applications will be affected advantageously by the addition of the additive of this invention. Generally these detergents are multicomponent systems, proprietary in nature, based upon anionic, cationic and/or non-ionic surfactants. Commonly included are (A) high molecular weight alkanolamides, typically the reaction product of an alkanolamine such as monoor diethanolamine with a fatty acid or ester having an alkyl residue of from 8-20 carbon atoms such as lauric or stearic acid; (B) alkali metal or ammonium salts of high molecular weight alkyl sulfate and sulfonates, the alkyl radical having at least 8 and preferably in excess of 12 and up to 22 carbon atoms, such as sodium lauryl sulfate and ammonium cetyl sulfonate; (C) salts of alkylbenzene sulfonic acids, the alkyl radical typically having from 8-20 carbons, such as the amine salt of linear dodecylbenzenesulfonic acid and sodium nonylbenzenesulfonic acid; (D) phosphate esters of non-ionic surfactants, such as the monoand diphosphate esters of polyoxyethylated dinonylphenol (average 4.5 moles ethylene oxide/mole phenol), potassium salt, as further described in US. 3,352,790; (E) high molecular weight alkyl quaternary ammonium halides, at least one alkyl group preferably containing from 8-20 carbons, such as lauryl dimethyl ammonium chloride; (F) adducts obtained by reacting from 1-20, preferably 2-10, moles of alkylene oxide such as ethylene or propylene oxide with (1) an alkylphenol, the alkyl radical preferred containing 4-18 carbons, such as nonylor dinonylphenol ethoxylated to an average of 4.5 moles of ethylene oxide/mole of phenol; (2) a high molecular weight alcohol, preferably aliphatic having from 6-20 carbons, such as tridecyl alcohol with 9.75 moles ethylene oxide and (3) a fatty acid, preferably aliphatic having 6-20 carbons, such as oleic acid with 15 moles of ethylene oxide; (G) amides of the foregoing adducts such as ethanolamides thereof and (H) tertiary amine oxides, typically having two lower alkyl radicals (C -C and one saturated or unsaturated alkyl radical of from 8-20 carbons, such as dimethyl hexadecylamine oxide. Often, a number of other ingredients such as lubricants, sweeteners, stabilizers and the like will be present, as well as small quantities of water to assist in the removal of water-soluble soils. Such detergent compositions may be present in the drycleaning system, depending upon a number of variables, Within the range of from 0.1-4.0 percent, by volume.

The additive compound useful for reducing or preventing the redeposition of soils on the textile fabrics is cal-v cium chloride. For the sake of convenience, because of its known tendency to absorb water and because a small amount of water is generally included in a drycleaning system in any event, the calcium chloride is usually added in the form of an aqueous solution, although other methods of providing the calcium chloride in solution in the solvent system are obviously equivalent. Amounts within the range are from 0.0l-2.0, preferably 0.05l.2 grams of calcium chloride, on an anhydrous basis, per 100 milliliters of drycleaning solvent are useful and may conveniently be provided in the form of an aqueous solution containing from 30-40 percent by weight of anhydrous calcium chloride. Obviously, larger amounts of calcium chloride may be employed but have not been found to substantially add to the beneficial effects sought.

The term textile fabrics is intended to apply to any of the materials commonly subjected to cleaning operations whether of natural or man-made fibers. Among the fabrics successfully treated to date are cotton, Dacroncotton, wool and rayon.

In order that those skilled in the art may readily understand the present invention, the following specific examples are afforded.

Example 1 To a wide mouth bottle are added 43 milliliters perchloroethylene, 0.115 ml. detergent (based on a high molecular weight alkanolamide), 1 ml. used automobile motor oil and 0.05 ml. 40 percent CaCl solution (aqueous solution, anhydrous basis). Two 4 inch by 4 inch swatches of 65/35 Dacron-cotton are added to the bottle, which is then covered and shaken for two minutes. The swatches are now removed from the bottle, squeezed to remove the excess perchloroethylene solution and placed in another bottle containing only 42 ml. of perchloroethylene and 0.15 ml. of the same drycleaning deter-gent. After further agitation for two minutes, the swatches are removed and it is observed that very little redeposition has occurred.

Identical swatches, treated in the same manner with the exception that the calcium chloride solution is replaced with a like amount of each of the following, show heavy redeposition: distilled water; 1% solutions of polyvinylpyrrolidone, sodium carboxymethyl cellulose, hydroxyethyl cellulose or polyvinyl alcohol; N Mg acetate, 5 N Mg sulfate and 5 N NaCl.

Example 2 According to the same procedure as Example 1, a 30%. solution of calcium chloride is used to evaluate the eifectiveness of this anti-redeposition agent over a range of concentrations. Eifectiveness is found to be excellent and approximately equal using 0.05, 0.125, 0.25, 0.50 and 1.0 ml. additions.

One milliliter additions of ammonium sulfate grams/ 100 ml. water), potassium carbonate (100 grams/ 100 ml.) and calcium nitrate (266 grams/100 ml.) are found to be ineffective.

Example 3 The test of Example 1 is repeated with the exception that ml. perchloroethylene, 0.125 ml. detergent, 1 ml. crankcase oil and 0.125 ml. of either distilled water or a 30% aqueous solution of calcium chloride is used. In place of the Dacron-cotton swatches, all cotton swatches are used. While the swatches treated in the solution containing the distilled water show heavy redeposition, those treated in the presence of the calcium chloride show almost no redeposition.

Example 4 The procedure of the preceding example is repeated, using both cotton and Dacron-cotton swatches, the changes being that the detergent used is different (based on an organic phosphate ester) and that the cleaning cycle is repeated five times. Again, redeposition is considerable in the absence of calcium chloride, but low in its presence.

Example 5 The preceding example is repeated with the exception that the amount of calcium chloride solution is increased to 1.0 ml. while the water is omitted completely from the control test. No change in results is noted.

Example 6 Into an 8 oz. jar are placed 42 ml. perchloroethylene, 1 ml. used crankcase oil, 0.15 ml. of a potassium salt of a phosphate ester of a ethoxylated dinonylphenoldimethyl-hexadecylamine oxide detergent (4 parts phosphate ester, 1 part amine oxide), either (A) 1 ml. of a 40% aqueous CaCl solution or (B) 0.6 ml. water and 2 swatches of 65/35 Dacron/cotton. After shaking for 2 minutes, the swatches are removed, squeezed dry and placed in a second jar containing 42 ml. perchlor and 0.15 ml. detergent where they are again shaken for 2 minutes. The dried swatches are read on a Hunterlab Model D25 Color Meter against a backing plate having the values L=95.0, a=(-)l.0 and b=2.4. The test swatches, prior to washing, have values of L=95.3 and W=l0l.2, W, the whiteness value being derived from the formula W=0.01L(L-5.72b). After testing, Sample (A) reads L=95.5, W=98.8 and Sample (B) without CaCl reads L=93.4, W=85.0.

While the invention has been described by reference to certain specific and preferred embodiments thereof it is,

not to be so limited since certain changes and alterations may be made which are within the scope contemplated by the appended claims.

I claim:

1. A composition for drycleaning textile fabrics which composition consists essentially of (a) a drycleaning solvent,

(b) from 0.1-4.0% by volume of a drycleanin detergent and (c) for each ml. of solvent, from 0.01-2.0 grams of calcium chloride.

2. A composition as in claim 1 wherein the drycleaning solvent is selected from the group consisting of trichloroethylene, perchloroethylene and Stoddards solvent.

3. A composition as in claim 1 wherein the calcium chloride is present as an aqueous solution thereof.

5 4. A method for reducing the tendency of a detergentcontaining drycleaning sol-vent to redeposit soils on textile fabrics which method consists essentially of adding 0.01- 2.0 grams of calcium chloride per 100 ml. of said solvent. 5. A method as in claim 4 wherein the calcium chloride is added as an aqueous solution.

References Cited UNITED STATES PATENTS 2,061,211 11/1936 Reddish 8142 3,345,123 10/1967 Chisholm 8142 3,393,154 7/1968 Treitler 252-162 6 OTHER REFERENCES Gregory: Uses and Application of Chemicals and Related Materials, Reinhold Publ. Co. 1939, pp. 136-138.

8142; 252172, Digest 15 

